ship.py

import pygame
from pygame.sprite import Sprite
class Ship(Sprite):
    def __init__(self,ai_settings,screen):
        super(Ship,self).__init__()
        self.screen = screen
        # 加载飞船图像
        self.ai_settings = ai_settings
        self.image = pygame.image.load('images/ship.bmp')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()
        # 每一艘飞船放在底下中间
        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom
        # 把像素点改为float值
        self.center = float(self.rect.centerx)
        self.moving_right = False
        self.moving_left = False
    def update(self):
        if self.moving_right and self.rect.right < self.screen_rect.right:
            self.center += self.ai_settings.ship_speed_factor
        if self.moving_left and self.rect.left > 0:
            self.center -= self.ai_settings.ship_speed_factor
        self.rect.centerx = self.center

    def blitme(self):
        self.screen.blit(self.image,self.rect)

    def center_ship(self):
        self.center = self.screen_rect.centerx